Besides the decision on lenses, the number one skill you will need is patience--lots of it! If you are shooting with a DSLR, but are simply not patient, then all you're doing is taking snap shots with expensive equipment.
I like to take my tripod, yes, even when I'm shooting in broad daylight. Why? It allows me to get better compositions. I can use a lower ISO and still get sharp photos. The best way I have found is to put my camera on the tripod, but loosen all knobs to allow me to move the perspective slightly, pan if I need to as the animal is moving, and switch quickly between verticals and horizontals. Sometimes, because the action is happening so quickly, I'll go ahead a get a couple of shots without my tripod before I lose the shots. If the action is still going on, then I'll place my camera on my tripod and keep shooting.
For you left-brain photographers, I shoot at JPEG fine (large files), usually ISO 200 (unless I need to hand hold my camera in shaded areas--but never higher than 800); set on vivid color.
Here are just a few of the many images I got at the Denver, Colorado Zoo recently.
When shooting through glass, put your lens right up against the glass to eliminate reflections/glare.
Patience allowed me to capture him looking straight at me.
A 200mm lens and patience was required to capture this hippo "posing" for me.
I spent at least 20 minutes photographing this hippo!
Patience. Patience. Patience.
The action and movements were happening so quickly. I used my multiple-frames-per-second feature to
make sure I got it just right. I liked this one for several reasons: You can see the dusting, the end of his trunk shows, there's a statue of a hippo in the background, and there are people walking around--an obvious zoo photo. And, yes, my camera on a tripod!
I hope I have given you some useful tips for you to go to your nearest zoo and have fun! Enjoy.